Chondrofix Osteochondral Allograft Prospective Study

Inclusion Criteria: Generally, the following inclusion criteria must be met, however, this is not a complete list. * Male and non-pregnant female subjects between 18 and 70 years; subject must be skeletally mature * If female, subjects are not pregnant at time of surgery and do not plan on becoming pregnant during the first 24 months of the study * Up to two (2) cartilage lesion(s), each measuring less than 8 cm2, of the femoral condyle or trochlear groove of the knee * Localized knee pain unresponsive to conservative treatment (e.g., medication, bracing, physical therapy) and/or previous surgical intervention Exclusion Criteria: Generally, if a potential participant meets any of the following criteria, they will not be eligible for this study. Additionally, more criteria will be evaluated to confirm eligibility as this list is not a complete list of criteria. * Concurrent participation in another clinical trial * Cartilage lesion location is such that the implanted graft(s) will not be adequately shouldered * Bipolar articular cartilage involvement (or kissing lesions) of the ipsilateral compartment (i.e., \> than ICRS Grade 2 on the opposing articular surface) * Is receiving pain medication other than NSAIDs or acetaminophen for conditions unrelated to the index knee condition * Subject had any other cartilage repair procedure other than debridement performed in conjunction with or 6 months prior to implantation of a Chondrofix Osteochondral Allograft * Prior or concurrent total meniscectomy of the index knee * Uncorrected mal-alignment of the index knee * Have smoked or used nicotine products within the past 6 months * Body Mass Index \> 35 (BMI=kg/m2) * Has any contraindications for MRI * Requires any of the following concomitant procedures performed in conjunction with or has had performed within 6 months prior to implantation of a Chondrofix Allograft: distal realignment, high tibial osteotomy, ligament reconstruction, and/or patellar realignment procedure * Septic or reactive arthritis or systemic disease (e.g., rheumatoid arthritis, gout or prior history of gout or pseudo gout) * Sickle cell disease, hemochromatosis, or autoimmune disease * Unstable cardiovascular, renal, hepatic, endocrine and/or pulmonary disease, cancer or uncontrolled diabetes * HIV or other immune-deficient state including subject on immunosuppressant therapies * Deficiency limiting ability to perform an objective functional assessment of the operative knee or an inability to adhere to a post-operative rehabilitation protocol